Dam Report

Willow Creek dam

South Dakota, USA Willow Creek Hazard High
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Dam height
49ft
Hazard rating
High
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Willow Creek -- None dam
Willow Creek None · Willow Creek
About this dam

Willow Creek

Willow Creek, located in Westport, South Dakota, is a vital water resource managed by the local government with oversight from the South Dakota Department of Agriculture and Natural Resources. The dam, constructed in 1934 by the Works Progress Administration (WPA), stands at a height of 49 feet and has a storage capacity of 7,650 acre-feet. With a drainage area of 155 square miles, the dam serves as a crucial flood control and water supply structure for the region.

The dam's spillway, with a width of 120 feet, is uncontrolled, allowing for the release of excess water during peak flow events. Willow Creek Dam is classified as having a high hazard potential, but its current condition is assessed as fair. Regular inspections are conducted every three years to ensure the dam's structural integrity and safety. Although the risk assessment indicates a moderate level of risk, the dam is equipped with vertical lift outlet gates to manage water levels effectively.

The presence of Willow Creek Dam underscores the importance of effective water resource management in mitigating flood risks and ensuring reliable water supplies for the surrounding community. Climate enthusiasts and water resource stakeholders can appreciate the dam's engineering design and the collaborative efforts involved in its operation and maintenance to safeguard the local ecosystem and residents from potential hazards.

StateNone
River / streamWillow Creek
NID IDSD00008
Owner typeLocal Government
Dam typeEarth
Year built1934
Dam height49 ft
Dam length1,330 ft
Max storage7,650 AF
Normal storage3,050 AF
Drainage area155.0 sq mi
Hazard potentialHigh
ConditionFair
Last inspectionWed, 13 Nov 2019 06:00:00 GMT

Dam data reference

Condition Assessment

Satisfactory
No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
Fair
No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action.
Poor
A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency.
Unsatisfactory
A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
Not Rated
The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.

Hazard Potential Classification

High
Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environmental damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
Low
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
Undetermined
Dams for which a downstream hazard potential has not been designated or is not provided.
Detailed forecast

Plan around the weather

Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.

Hourly detail

Next 5 days, hour by hour

Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.

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Deep dive

5-day forecast table

Every 3 hours, broken out across temperature, snow, rain, humidity, and wind. Each cell is colour-coded relative to the column min/max.

TimeConditionTemp (°F)Snow (in)Rain (in)Humidity (%)Wind (mps)Wind dir
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Long-term outlook

15-day temperature & precipitation

Daily temperatures, snow, and rain projected over the next two weeks.

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Regional inflow

Nearby streamflow gauges

USGS streamgauges around Willow Creek -- inflows here typically show up in storage 24-72 hours later.

Track Willow Creek in the Snoflo app

Save this dam as a favorite and get the local NOAA / yr.no forecast plus regional flow context wherever you are.

FAQ

About Willow Creek

Where does the data for Willow Creek come from?

Structural and regulatory data come from the U.S. Army Corps of Engineers' National Inventory of Dams (NID). Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.

How often is the report updated?

NID structural data refreshes annually as the Corps publishes updated assessments. The weather forecast refreshes throughout the day.

What does the High hazard rating mean?

The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card above for the full definitions.

What's "% of normal"?

The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).

Can I get alerts when storage crosses a threshold?

Yes -- alerts are managed in the Snoflo iOS app. Favorite this dam, set a threshold, and you'll get a push the moment conditions cross.

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